I hate when I get my car messed with, I can't count how many time I came out to my highschool parking lot and found somethign wrong with my car. I never did anything to anyone. I came out one time and my whole car, Im talking about every inch, the roof, windows, rims, everything was covered in yellow post-its, not to mention so many other things.
Messing with cars is strickly wrong, unless its payback after having your car messed with, or something really bad. Its always the damn people who don't have cars that always mess with myne. They don't know the money that goes into these things or the sweat and hard work.
But this is definately grounds for pay back. Whatever you do, do it right and make sure he pays. I have always wanted to jack someones car up and put blocks of wood underneath the axles so that the tire is just off the ground, and they don't notice anything and go to drive away and can't move, and will have no clue whats going on.